FAMILY SCOLYTIDAE 485 



were in the upper branches in the crown of the tree. There can be little 

 doubt that the beetle, as is the case with Sphaerotrypes siwalikensis, tunnels 

 into green shoots for feeding purposes only, and in areas of coppice and 

 young plantations would prove a serious pest in this connection. 



Methods for the protection of forests from the attacks of bark-boring 

 pests of this nature have already been discussed when 



of Protection considering the life history of Sphaerotrypes siwalikensis, 



and it will be unnecessary to detail them again here. 



The method of ascertaining the numbers of the insects in the forest and 

 of trapping them by using felled trees as described under Hoplocerambyx can 

 also be resorted to in the case of this insect. In May the same trees will do 

 for both, since at least one generation of the Sphaerotrypes, and probably the 

 March one also, will coincide with the appearance of the Hoplocerambyx 

 beetles in the forest. For the other periods only the trap trees should be 

 destroyed, i.e. barked and the bark burnt (the timber is not affected by this 

 insect), when the beetle is not on the wing in the forest, i.e. when the insect 

 is in the bark and sapwood either as larvae, pupae, or immature beetles. 



Niponius andrewesi, Lewis, (p. 102). This insect was first taken in 

 Assam in May 1906, when it was found preying upon the sal Sphaerotrypes 



described above. It has alreadv been shown that it has 

 Predaceous Insects. 



a wide distribution throughout the country. 



Life History, The following are supplementary notes on the life history 

 of the Xiponius as observed in Assam in April and May : 



Larvae were taken in the galleries of the mature grubs of Sphaerotrypes 

 in the Hultugaon forests at the end of April. On 14 May I took a 

 specimen of the beetle in a partially complete egg-gallery of a Sphaerotrypes. 

 The bark-boring beetles had apparently been eaten by it. On the 2ist of the 

 month I took a number of beetles engaged in devouring the bark-borers which 

 were attacking the large green sal -tree mentioned on p. 484. In addition to 

 searching out the bark-boring beetles I think the histerid also enters the 

 egg-galleries for the purpose of laying its eggs close to those of the Sphaero- 

 trypes. The pink grub is, however, very active, and does not appear to 

 confine itself to any one set of larval galleries, since it is often found between 

 the bast and sapwood worming its way on to neighbouring galleries remote 

 from the one where it hatched out. The eggs of the Xiponins do not hatch 

 as soon as, or at the same time as, those of the bark-borer, since no young 

 larvae were present in any of the egg-galleries and short larval galleries found 

 so numerously in the latter half of May. The abundance of this insect is by 

 no means yet satisfactorily settled. In the three localities I have found it 

 in it has only been sparingly taken. This may. however, be easily accounted 

 for by the fact that it is only to be found in the larval galleries of its 

 host, from which it has to be laboriously cut out. I have rarely taken 



